@@ -373,7 +373,7 @@ struct cpu_vfs_cap_data {
#define CAP_TO_MASK(x) (1 << ((x) & 31)) /* mask for indexed __u32 */
#ifdef __KERNEL__
-
+struct file;
struct dentry;
struct user_namespace;
@@ -548,6 +548,7 @@ extern bool has_ns_capability_noaudit(struct task_struct *t,
extern bool capable(int cap);
extern bool ns_capable(struct user_namespace *ns, int cap);
extern bool nsown_capable(int cap);
+extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap);
/* audit system wants to get cap info from files as well */
extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps);
@@ -393,6 +393,30 @@ bool ns_capable(struct user_namespace *ns, int cap)
EXPORT_SYMBOL(ns_capable);
/**
+ * file_ns_capable - Determine if the file's opener had a capability in effect
+ * @file: The file we want to check
+ * @ns: The usernamespace we want the capability in
+ * @cap: The capability to be tested for
+ *
+ * Return true if task that opened the file had a capability in effect
+ * when the file was opened.
+ *
+ * This does not set PF_SUPERPRIV because the caller may not
+ * actually be privileged.
+ */
+bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap)
+{
+ if (WARN_ON_ONCE(!cap_valid(cap)))
+ return false;
+
+ if (security_capable(file->f_cred, ns, cap) == 0)
+ return true;
+
+ return false;
+}
+EXPORT_SYMBOL(file_ns_capable);
+
+/**
* capable - Determine if the current task has a superior capability in effect
* @cap: The capability to be tested for
*